Wide field around Altair with unknown object

[rotatux]

Hello,

Having some free time I just processed this image taken on 2018-08-12 and discovered a comet-like object besides Altair and Tarazed, but I don't see it in Stellarium. Given the greenish tint (on my laptop, compared with blue Altair and orange Tarazed) I suspect a comet, but Stellarium searches don't work and anyway I don't know how to search by sky position.

Anyone an idea ?

Taken with Minolta MD Rokkor 50mm/1.7 at f/4.0 with u4/3 (MFT) camera, left of original image has been truncated, then it was reduced 75%.

[coatesg]

I don't think there's any bright comets in that region of the sky - I strongly suspect it's lens flair/internal reflection as Altair is v bright. There is some quite faint nebula in that region, but not quite there - see the (stretched!) DSS image below:

You have captured Barnard's "E" (B142/B143) nicely there though!

 

[rotatux]

Thanks, I never had the slighest reflection with that lens, even with other bright stars, so I had disfavoured that possibility.

Anyway by coincidence the bright star is near center and I know my camera's sensor is not pixel-centered under the lens, so this must be a reflexion. Strange for the slight color shift, that must be the coating.